"Terrian, Tom" wrote:
>
> I think that this subject comes up now and then, but I don't remember the
> conclusions........
>
> We are creating a Data Warehouse and the subject of char vs varchar2 data types
> came up. I searched google and found a little bit on the subject (mainly there
> is no space savings between char(1) and varchar2(1)).
>
> Has anybody studied this? For example: If I know that all my data is 10
> characters wide, should I not create the field as char(10)? Any reason to make
> it a varchar2(10)? Would sql scripts (select and dml) be faster with one type
> or the other? Any space savings with one type or the other (still given 10
> characters of fixed data)?
>
> Thanks,
> Tom
>
> Tom Terrian
> Oracle DBA
> WPAFB - DAASC
> [EMAIL PROTECTED]
> 937-656-3844
Tom,
There is a somehow astonishingly little known - in spite of its having
been around for at least the 15 last years - SQL function named VSIZE()
which answers any question you may have about actual storage usage. For
the really inquisitive, you have DUMP() as well.
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Stephane Faroult
Oriole Corporation
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Fax: +44 (0) 7050-696-449
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Author: Stephane Faroult
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